dm: remove dm header from targets

Change #include "dm.h" to #include <linux/device-mapper.h> in all targets.
Targets should not need direct access to internal DM structures.

Signed-off-by: Mikulas Patocka <[email protected]>
Signed-off-by: Alasdair G Kergon <[email protected]>
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 5b48478..a8c0fc7 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -12,7 +12,7 @@
 #include <linux/dm-io.h>
 #include <linux/dm-dirty-log.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "dirty region log"